Commit ec7fafa6 authored by Xin Long's avatar Xin Long Committed by Greg Kroah-Hartman

tipc: change to use register_pernet_device

[ Upstream commit c492d4c7 ]

This patch is to fix a dst defcnt leak, which can be reproduced by doing:

  # ip net a c; ip net a s; modprobe tipc
  # ip net e s ip l a n eth1 type veth peer n eth1 netns c
  # ip net e c ip l s lo up; ip net e c ip l s eth1 up
  # ip net e s ip l s lo up; ip net e s ip l s eth1 up
  # ip net e c ip a a 1.1.1.2/8 dev eth1
  # ip net e s ip a a 1.1.1.1/8 dev eth1
  # ip net e c tipc b e m udp n u1 localip 1.1.1.2
  # ip net e s tipc b e m udp n u1 localip 1.1.1.1
  # ip net d c; ip net d s; rmmod tipc

and it will get stuck and keep logging the error:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

The cause is that a dst is held by the udp sock's sk_rx_dst set on udp rx
path with udp_early_demux == 1, and this dst (eventually holding lo dev)
can't be released as bearer's removal in tipc pernet .exit happens after
lo dev's removal, default_device pernet .exit.

 "There are two distinct types of pernet_operations recognized: subsys and
  device.  At creation all subsys init functions are called before device
  init functions, and at destruction all device exit functions are called
  before subsys exit function."

So by calling register_pernet_device instead to register tipc_net_ops, the
pernet .exit() will be invoked earlier than loopback dev's removal when a
netns is being destroyed, as fou/gue does.

Note that vxlan and geneve udp tunnels don't have this issue, as the udp
sock is released in their device ndo_stop().

This fix is also necessary for tipc dst_cache, which will hold dsts on tx
path and I will introduce in my next patch.
Reported-by: default avatarLi Shuang <shuali@redhat.com>
Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Acked-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a061216a
......@@ -132,7 +132,7 @@ static int __init tipc_init(void)
if (err)
goto out_sysctl;
err = register_pernet_subsys(&tipc_net_ops);
err = register_pernet_device(&tipc_net_ops);
if (err)
goto out_pernet;
......@@ -140,7 +140,7 @@ static int __init tipc_init(void)
if (err)
goto out_socket;
err = register_pernet_subsys(&tipc_topsrv_net_ops);
err = register_pernet_device(&tipc_topsrv_net_ops);
if (err)
goto out_pernet_topsrv;
......@@ -151,11 +151,11 @@ static int __init tipc_init(void)
pr_info("Started in single node mode\n");
return 0;
out_bearer:
unregister_pernet_subsys(&tipc_topsrv_net_ops);
unregister_pernet_device(&tipc_topsrv_net_ops);
out_pernet_topsrv:
tipc_socket_stop();
out_socket:
unregister_pernet_subsys(&tipc_net_ops);
unregister_pernet_device(&tipc_net_ops);
out_pernet:
tipc_unregister_sysctl();
out_sysctl:
......@@ -170,9 +170,9 @@ static int __init tipc_init(void)
static void __exit tipc_exit(void)
{
tipc_bearer_cleanup();
unregister_pernet_subsys(&tipc_topsrv_net_ops);
unregister_pernet_device(&tipc_topsrv_net_ops);
tipc_socket_stop();
unregister_pernet_subsys(&tipc_net_ops);
unregister_pernet_device(&tipc_net_ops);
tipc_netlink_stop();
tipc_netlink_compat_stop();
tipc_unregister_sysctl();
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment